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Foob being a combination of food and boob, the Foob Theorum is the idea that when a girl wears a low-cut top food will always fall between her boobs when trying to eat.
Jenny- "I was eating popcorn last night at the movies, and I got a bunch down my shirt."

Joe- "A fine example of the Foob Theorum."
by Lerfer September 02, 2012